The present invention relates to an ultrasonic actuator which generates a driving force.
In recent years, as an example of ultrasonic actuators of this kind, an ultrasonic actuator disclosed by Patent Document 1 has been known. This ultrasonic actuator includes an actuator body including a piezoelectric element having four electrodes provided at different positions. AC voltages having different phases are applied to two electrode pairs of the actuator body, each of which includes two electrodes diagonally arranged, so as to harmonically induce longitudinal and bending vibrations, thereby generating a driving force.
According to Patent Document 1, the actuator body is elastically supported on a base member so that the vibrations of the actuator body are not hindered. For example, Patent Document 1 discloses a structure in which the actuator body is elastically supported in a case serving as the base member.
[Patent Document 1] Published Japanese Patent Application No. H8-237971